Student Involvement

Steven Michael Lusher; Senior Research Specialist (PhD Candidate)

Project Objective

The overall project objectives include the acquisition of a high-quality temperature chamber with a range of -30°C to +100°C that can be integrated with the MTS 880 load unit and/or other appropriate load frames that already exist within the Department of Civil, Architectural, and Environmental Engineering at the University of Missouri-Rolla.

Project Abstract

With the Missouri Department of Transportation (MoDOT) beginning to implement the new Mechanistic-Empirical (M-E) Design Guide for New and Rehabilitated Pavements, the need exists for various types of testing of hot-mix asphalt (HMA) mixes used by MoDOT in its flexible pavements. In particular, the American Association of State Highway and Transportation Officials (AASHTO) test protocol T 322 is utilized to determine HMA properties needed as inputs to pavement distress prediction models within the M-E Pavement Design Guide (MEPDG) Software. The primary properties derived from T 322 are creep compliance and tensile strength. These properties are determined using indirect tension methods and are temperature dependent. Creep compliance is a parameter used in the thermal cracking distress model within the MEPDG Software and is determined at 0, -10, and -20°C while tensile strength is an input to the fatigue cracking distress model and is determined at temperatures ranging from -20 to +20°C.

MoDOT has expressed the desire to have UMR perform the T 322 testing on several HMA mixes used in wearing (surface) courses throughout the state. MoDOT needs the T 322 results to calibrate default distress models currently employed in the MEPDG Software. The Department of Civil, Architectural, and Environmental Engineering (CArE) has an MTS 880 load unit that is capable of meeting T 322 specimen loading specifications. However, a high-quality temperature chamber that can be configured with the MTS 880 needs to be acquired in order to comply with the bulk (dollar-wise) of the remaining T 322 testing equipment specifications.

Anticipated Benefits

According to NCHRP Report 530 (2004), only about a dozen laboratories in the United States regularly perform low-temperature indirect tensile testing of HMA. Availability of a spacious, high-quality temperature chamber that will reside in the CArE department, coupled with a sophisticated load unit such as the MTS 880, will enhance the transportation and materials research activities of faculty and students at UMR.

Modal Orientation

Construction Materials Testing

Milestones

Project Start Date:

03/01/2006

Project End Date:

12/1/2007

Relationship to other Research/Projects

Acquisition of the temperature chamber would increase the potential for performing static or dynamic loading of other transportation construction materials (metals, composites, etc.) at a wide range of temperatures.